function GrandParent() {
    this.name = 'grandparent'
    this.card = 'visa'
}

function Parent() {
    this.lastName = '张'
}

function Child() {
    this.name = '张三'
    this.age = 18
}

const c = new Child()

console.log(c.lastName) // 张
console.log(c.card)  // visa

